A tractor trailer overturned Monday, spilling tons of scrap metal onto a major street in Colton.

About 10:15 a.m., the driver of the truck was exiting the eastbound 10 Freeway and turning left onto Mt. Vernon Avenue when the trailer overturned, Colton police Sgt. Alan Koahou said. The truck crashed into a guard rail, spilling the contents inside the trailer.

There were no injuries, Koahou said, and the only damage was to a light post on the guardrail.

The spilled scrap metal affected southbound traffic on Mt. Vernon, between Valley Boulevard and M Street, and lanes were shut down for about three hours. The crash was cleared about 1:30 p.m., Koahou said.